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CFDLife August 1, 2008 17:07

Queueing the simulations
I am running my simulations on Intel dual core processor (windows based). I have parallel licensing using.

Is there a way I can queue up a few runs, so that the machine can keep working even when i am away?

In other words, how do i create a batch file to run in ANSYS CFX to queue up the simulations.

I read other post where it was mentioned but i guess it was for cfx5 and doesnt work in ANSYS CFX.

Thanks in advance

Rogerio Fernandes Brito August 1, 2008 18:45

Re: Queueing the simulations
there is a way u can queue up a few runs, then the machine can keep working even when i am away! I just decrease the priority of run, task bar of windows, using low!

Amit Roghs August 2, 2008 04:16

Re: Queueing the simulations
Write the following perl program to have a batch mode run in sequence.

use strict;

system "cfx5solve -def your file name.def";

system "cfx5solve -def your second file name.def";

After writing the above text in a notepad save it as .pl file extension & give the file name what you wish, I am taking

Then type the following in the command prompt of CFX in your working directory of above files.


The run will start automatically & when first run is over the other will start automatically.

Do let me know if you have any queries.


Amit Roghs

Glenn Horrocks August 3, 2008 18:37

Re: Queueing the simulations

Rogerio's suggestion is a very poor way of doing it. It uses many licenses and also fills up your system memory. Amit's posting shows how to do it using perl but it is much easier to just write a simple batch (Windows) or shell script (unix/linux) and queue them that way.

eg, in windows create a file called "doruns.bat" which contains: cfx5solve -definition run1.def cfx5solve -definition run2.def cfx5solve -definition run3.def cfx5solve -definition run4.def

Run the batch file (using a command line started from the CFX launcher window) and they will be queued up.

Glenn Horrocks

CFDLife August 4, 2008 16:18

Re: Queueing the simulations
Thanks to all of you, I did what u suggested.

When I run the perl in the command prompt, it says - 'perl' is not recognized as an internal or external command, operable program or batch file.

Is there any solution to this problem?

Amit Roghs August 5, 2008 01:07

Re: Queueing the simulations
You should run the perl from the Ansys CFX command prompt.

CFDLife August 5, 2008 09:13

Re: Queueing the simulations
Ok..Here is what i did:

Open a *.cfx file in ANSYS CFX-Pre. Clicked on Tools - > Command Editor Wrote and Hit Process (My file name is

I got an error saying

CCL parser failed with message parseCCLineH: syntax error near

Glenn Horrocks August 5, 2008 20:13

Re: Queueing the simulations

Unless you are going to use the functionality of perl (looping, if/then, subroutines etc) then forget perl and use a simple batch script. If all you want to do a sequence of simulations it is much easier.

Glenn Horrocks

Amit Roghs August 6, 2008 00:21

Re: Queueing the simulations
Dude you dont have to do that in *.cfx

I will write down the steps below.

1.Open the Ansys CFX Launcher(not ansys CFX Pre)

2.Go to Tools

3.There you have any option of command prompt.

4.Once you click it there will be a DOS window opening.

5.After that you gotta write perl

6.The job will start running automatically.

7.You wont be able to see it directly.

8.Now open the CFX Solver.

9.Go to File Menu,click Monitor Run in Progress.

10.Give path to the working directory where it is being run.

11. You will be able to see the run convergence and the run details as usual.

If you still dont get the procedure then do let me know.


Amit Roghs

AGP December 1, 2014 17:42

Is there any way to do the same thing in FLUENT?

ghorrocks December 2, 2014 01:54

Fluent can be run from the command line so you can do it there. I suspect it can also be run through workbench so that is another way. You can also use batch scheduling software like PBS of LSF.

Try the fluent form for details.

ZakBristol February 25, 2016 21:42

I have created this batch file , and I got this error.

Unknown command line option year

cfx5solve -definition G:\Final Year Project\Different Pitch\-6.25 -6.25Degree.def
cfx5solve -definition G:\Final Year Project\Different Pitch\-7.5\-7.5Degree.def
cfx5solve -definition G:\Final Year Project\Different Pitch\-8.75\-8.75Degree.def

ghorrocks February 25, 2016 21:45

Your file path has spaces in it. This confuses the command line interpreter. So put your path in quotes:

cfx5solve -definition "G:\Final Year Project\Different Pitch\-6.25 -6.25Degree.def"

Thomasbr June 23, 2016 10:21


this topic is pretty old, but as I have a question which relates to it... (I searched the web and the forum but couldn't really find what I was looking for as the Scripting things are not very familiar...)

Let us say I want to queue up 3 simulations using a Batch (or Perl) file as suggested by ghorrocks (in the simulations only one Parameter is modified, for instance the 1st with Viscous Work, the 2nd without, and the third with High Speed Compressible Wall Heat Transfer).

I need to do this for the week-end because I cannot go to work during it, I would like to start Simulation 1 on friday in the afternoon and then when S1 is finished, I'd like that S2 starts automatically right after and then so does S3.

Should I make 3 different projects, which results in:
  • U:\Thomas\Simulation1_files\dp0\CFX\CFX\Fluiddynamik CFX.def
  • U:\Thomas\Simulation2_files\dp0\CFX\CFX\Fluiddynamik CFX.def
  • U:\Thomas\Simulation3_files\dp0\CFX\CFX\Fluiddynamik CFX.def
Should I make 1 project with 3 duplicated jobs in it, which results in:
  • U:\Thomas\Simulations_files\dp0\CFX\CFX\Fluiddynamik CFX.def
  • U:\Thomas\Simulations_files\dp0\CFX-1\CFX\Fluiddynamik CFX.def
  • U:\Thomas\Simulations_files\dp0\CFX-2\CFX\Fluiddynamik CFX.def
Or even something else?
Because with the two things I propose, the *.def files are never in the same directory.


ghorrocks June 23, 2016 19:47

This is simple:

cd /path/to/first/directory
cfx5solve -def DefinitionFile1.def
cd /path/to/second/directory
cfx5solve -def DefinitionFile2.def


Thomasbr June 24, 2016 09:18

1. Thanks again for your reply Glenn: I managed to make something work, but only with the command line of the CFX Launcher.

I pasted this into the command prompt (displayed after I launched it via CFX launcher):

cd U:\Thomas\Simulation1_files\dp0\CFX\CFX
cfx5solve -def "Fluiddynamik CFX.def"

cd U:\Thomas\Simulation2_files\dp0\CFX\CFX
cfx5solve -def "Fluiddynamik CFX.def"

and both simulations are launched one after another as wanted :)

2. The Batch file doesn't work and if I try to do it manually with the command prompt launched via cmd.exe (and not via the CFX Launcher) it doesn't work either because it seems that it doesn't understand 'cfx5solve'.
But as the other method works, it's ok to me.

Batch file:
REM I need to change the drive from C:\ to U:\ first

cd U:\Thomas\Simulation1_files\dp0\CFX\CFX
cfx5solve -def "Fluiddynamik CFX.def"

cd U:\Thomas\Simulation2_files\dp0\CFX\CFX
cfx5solve -def "Fluiddynamik CFX.def"


3. Do you know how to tell CFX to use "Double Precision"? I tried this (as I could read it in the documentation):

cfx5solve -def "my file.def" [-double]

But [-double] is not recognized.

-Maxim- June 24, 2016 09:26

You either need to launch it from CFX' command line or add the full path to the cfx5solve.exe:

"C:\Program Files\ANSYS Inc\v171\CFX\bin\cfx5solve.exe" -batch -double -par-local -partition NUMBER OF CPU CORES -def yourDEF.def -cont-from-file "path/to/old/result.res" -priority 1
If you set the whole path in "", you won't get problems with spaces in the path name.

In windows batch (launching from cmd.exe) you could work with "variables" as well:

SET ansyspath="C:\Program Files\ANSYS Inc\v171\CFX\bin\cfx5solve.exe"
and then call the variable with

%ansyspath% -def YOURDEF.def etc
edit: additional, you could launch your files from anywhere without have to "cd" into the right directory by just using the full path to your def file:

"C:\Program Files\ANSYS Inc\v171\CFX\bin\cfx5solve.exe" -batch -double  -par-local -partition NUMBER OF CPU CORES -def "U:\Thomas\Simulation1_files\dp0\CFX\Fluiddynamik CFX.def"

Thomasbr June 24, 2016 09:58

Thank you very much Maxim :)

I did not know these tricks (sorry for being such a newbie) and it helps me a lot!

Thomasbr June 27, 2016 05:30


it worked thanks again :) The 3 results files are available to be analysed which is rather pleasant.
But it seems something went wrong with the Double Precision: below is the beginning of the .out file:


This run of the CFX Release 16.0 Solver started at 16:17:34 on 24 Jun
2016 by user thomasb on CAD-103-3 (intel_xeon64.sse2_winnt) using the

"C:\Program Files\ANSYS Inc\v160\CFX\bin\perllib\" -def
"U:\Thomas\triplette-test_files\dp0\CFX\CFX\sans viscous work.def"

Release 16.0

Point Releases and Patches installed:
ANSYS, Inc. Products Release 16.0
ANSYS Mechanical Products Release 16.0

Setting up CFX Solver run ...

| |
| CFX Command Language Upgrade |
| |
Precision = Off

| |
| CFX Command Language for Run |
| |
MATERIAL: Air Ideal Gas
What do you think?
Does it really mean that the calculations have been performed using simple numerics precision? :(

EDIT: I definitely think yes, because there is a huge difference in the calculation time (and therefore in the number of time steps and the values of them).

With the same mesh I have:

Double Precision Enabled (old Simulation)
13 hours calculation time, 12500 timesteps, last timestep=6,77e-07s

Double Precision Off (simulations performed in the week end)
9 hours calculation time, 8700 timesteps, last timestep=2,2e-05s

---> Though RMS criterion <1e-4s is in both cases fulfilled, the Courant Number with Single Precision Numerics gets rather high

ghorrocks June 27, 2016 06:56

Yes, you are correct - you have not used the -double argument correctly so it has not been activated. Please post your batch file and we will try to help you.

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